public EvaluatorResult Evaluate(IInterpreterContext context, string expression)
{
string LeftValue;
try
{
if (checkForExistence)
{
var res = context.PropertyExists(leftSide);
// just check existence, nothing else, or it does not exist
if (res == false || NoRightSide)
{
if (IsNegate)
{
res = !res;
}
return(new EvaluatorResult(res, string.Empty));
}
}
// existence of property is assumed (it is either checked or no "?" was present
if (evaluator is Evaluator.ExpressionEvaluator)
{
LeftValue = context.EvaluateProperty(leftSide);
}
else
{
var evalRes = evaluator.Evaluate(context, leftSide);
if (evalRes.Result == EvaluationResultValues.True)
{
LeftValue = evalRes.Value;
}
else
{
LeftValue = "error";
}
}
}
catch (Exception ex)
{
return(new EvaluatorResult(ex));
}
LeftValue = LeftValue.ToLower();
bool retVal;
if (CompareEqual)
{
retVal = LeftValue == rightSide;
}
else
{
retVal = LeftValue != rightSide;
}
// leading "!" is valid for the complete if-clause
if (IsNegate)
{
retVal = !retVal;
}
return(new EvaluatorResult(retVal, string.Empty));
}